I use a wdh with my 25 footer and a 2500HD. It doesn't steer better with it on there but it rides better- it cuts down on porpoising. Plus there's no way for the hitch to pop off the ball with the bars in place.

When we bought our 24' last year, I had no idea what I was doing and just had a 2 5/8" ball, hooked her up and drove down over an hour doing 65-70 the entire way. Never had an issue. Big trucks didn't bother it at all. Then again, the TV is a Mega Cab so wheelbase is nice and long. I do use one now (we also purchased a longer TT). Is it necessary? Maybe not. Would it give you peace of mind? Only you can answer that.